1. Field of the Invention
The present invention concerns the secure engagement of a holding device for a system for clamping two members. The clamping system has a clamping pin that passes through each of the two members. This secure engagement arrangement for a holding device is applicable in particular to an automobile vehicle steering column, the steering column being adjustable in height and/or in depth in the vertical plane.
2. Description of the Prior Art
In an adjustable automobile steering column, the system for adjusting the height in the vertical plane or the depth in the vertical plane requires the position chosen by the driver to be maintained. In prior art devices there is provision for adding to the clamping system of the position adjustment system a device with metallic teeth connected to each of the two members to be clamped so that the metallic teeth come into contact with each other to guarantee that the chosen position is maintained. The teeth are on the one hand on a fixed rack forming part of the support member and on the other hand on a rack mounted on the mobile adjustment system. In certain heightwise adjustment positions the tops of the teeth of the mobile rack can come into contact with the tops of the teeth of the fixed rack when the device is being locked. The rack system is then in a position of unstable equilibrium, leading to two situations:
the tops of the teeth remain in equilibrium, the locking system cannot operate, and it is impossible to lock the column adjustment system; PA1 on application of additional force to the operating lever, the tops of the teeth leave this unstable position and take up a position in the gaps between teeth, so that the system can be locked. However, this movement from the equilibrium state to the locked state is accomplished with a slight impact within the rack system and this causes a cracking noise and a "hard point" feeling in the operating lever. Although they have no effect on the functioning of the locking system, these phenomena are perceived as being disagreeable and can therefore be considered unacceptable. Such phenomena compromise the mechanical strength of the device and make the driver feel insecure. PA1 additional spring means mounted on the clamping pin against the mobile rack and on the same side as a clamping means mounted on an end of the clamping pin; PA1 a bracket mounted on the clamping pin between the additional spring means and the clamping means; and PA1 the additional spring means and the bracket being shaped and adapted so that in the locked position of the clamping system: PA1 the first member is a body tube of an automobile vehicle steering column, the column being adjustable in at least one of the heightwise and depthwise adjustment directions in the vertical plane; PA1 a steering shaft is mounted to rotate freely in the body tube; PA1 the second member is a support member attached to the chassis of the vehicle; PA1 in an adjustment system for adjusting the position of the steering column, the body tube or first member is disposed in the support member or second member, the clamping system is in the unlocked position, the first member is placed at a required position relative to the second member by the adjustment system, and the first member is immobilized relative to the second member in the locked position by the clamping system. PA1 a bearing face which is provided with positioning studs for positioning it into the second member; PA1 two contact faces which are oriented in the adjustment direction and which are disposed on respective opposite sides of an oblong hole through which the pin of the clamping system can pass and allowing movement of the clamping pin during positional adjustment; and PA1 two paths which are provided with teeth, the paths being oriented in the adjustment direction and extending along the contact faces respectively. PA1 a hole through which the clamping pin passes, PA1 a bearing face for the additional spring means, PA1 two contact faces for the return spring disposed around the hole, PA1 two paths provided with teeth, oriented in the adjustment direction and extending along the contact faces respectively, and PA1 two opposite central notches adapted to receive the two tongues of the return spring respectively.